Motion simulator

ABSTRACT

A motion simulator having a stationary frame and a movable frame below the stationary frame in the direction of gravity. A passenger car is attached to the bottom surface of the movable free. A driving device is located between the stationary frame and the movable frame and rotationally or linearly moves the movable frame.

BACKGROUND OF THE INVENTION

This invention relates to a motion simulator, and particularly animproved motion simulator in which occurrence of undesired movingsensations are eliminated during the creation of moving sensations usinggravity and thereby creation of a moving sensation which is more similarto the actual situation is possible.

Generally, a motion simulator refers to a device which simulates motionsof objects such as an airplane or an automobile and allows people tofeel moving sensations within a limited space.

As a general motion simulator such as the above, a 6 DOF (degree offreedom) motion simulator (100) in which a movable frame (120) is drivenby six actuators (131, 132, 133, 134, 135, 136) is depicted in FIGS. 1to 3 b.

As depicted in FIG. 1, the conventional 6 DOF motion simulator(100) hasa structure which includes a stationary frame (110), a movable frame(120), and a plurality of actuators (131, 132, 133, 134, 135, 136).

Said stationary frame (110) is installed fixedly against the ground(gravity field). Said movable frame (120) is disposed above thegravitational direction of the stationary frame (110). A passengercompartment (140) is disposed on the top surface of said movable frame(120).

Said plurality of actuators (131, 132, 133, 134, 135, 136) are disposedbetween the stationary frame (110) and the movable frame (120).Electric, hydraulic, or pneumatic actuators are generally used for eachof said actuators.

Said each actuator (133, 132, 133, 134, 135, 136) is rotatably connectedat both ends thereof by respective pairs of universal joints (131 a and131 b, 132 a and 132 b, 133 a and 133 b, 134 a and 134 b, 135 a and 135b, 136 a and 136 b).

The conventional 6 DOF motion simulator (100) configured as the aboveallows the passenger (170) in the passenger compartment (140) to feelmoving sensations similar to those felt when actually riding an airplaneor automobile by driving the plurality of actuators (131, 132, 133, 134,135, 136) and thereby moving the movable frame (120).

For instance, for a racing car that has suddenly taken off and continuesto accelerate, the passenger feels sensations of being pulled backwarddue to acceleration, and this sensation is continued while accelerationafter start is being progressed.

To create such sensation, the motion simulator (100) drives theplurality of actuators (131, 132, 133, 134, 135, 136) and firstlyaccelerates the movable frame (120) forward, as depicted in FIG. 2a. Inthe above case, the passenger (170) within the passenger compartment(140) feels a pulling sensation from the rear to the force of inertia.

However, because the range of motion of the motion simulator (100) has alimit, the movable frame (120) which has been accelerated and movedforward shortly falls within this limit. At this time, as depicted inFIG. 2b, when the front of the movable frame (120) is lifted, thepassenger (170) continues to feel said sensation due to gravity.

On the other hand, as another example, for an automobile turning along alarge curve, the passenger feels a pushing sensation to the outerdirection of the curve due to centrifugal force, and continues to feelthis sensation while the turning is being progressed.

To create such sensation, the motion simulator (100) actuates theplurality of actuators (131, 132, 133, 134, 135, 136) and firstlyaccelerates the movable frame (120) to the side director, as depicted inFIG. 3a. In the above case, the passenger (170) within the passengercompartment (140) feels a sensation of being pushed in the oppositedirection of said movement due to the force of inertia.

However, also for this case, because the range of motion of the motionsimulator (100) has a limit, the movable frame (120) which has beenaccelerated and moved to the side direction shortly falls within thislimit. At this time, as depicted in FIG. 3b, when the side of themovement direction of the movable frame (120) is lifted, the passenger(170) continues to feed said sensation.

On the other hand, in FIGS. 4 to 6, as another example of theconventional motion simulator, a 3 DOF motion simulator (101) of whichthe movable frame (120) is driven by three actuators (131′, 132′, 133′)is depicted.

According to FIGS. 4 to 6, the configuration of the conventional 3 DOFmotion simulator (101) is identical to that of the 6 DOF motionsimulator except that the former has three actuators (131′, 132′, 133′and that it is provided with a separate support member (150) to limitthe occurrence of unintended forward/backward linear motion, left/rightlinear motion, and rotating motion centered on the top, bottom axesperpendicular to the surface of the movable frame (120).

Therefore, in describing the configuration of the 3 DOF motion simulator(101), same reference numbers are designated for parts identical tothose of the 6 DOF motion simulator, and the descriptions thereof areomitted.

Meanwhile, as mentioned above, because all motions of the movable frame(120) can not be restrained with only the actuators (131′, 132′, 133′),in the depicted conventional 3 DOF motion simulator (101), there isprovided a separate support member (150) for limiting the occurrence ofunintended motion to the movable frame (120).

Said support member (150) is composed of a cylinder (151) which is fixedon the stationary frame (110), a piston (152) which moves up and downalong said cylinder, and a universal joint (153) which connects saidpiston and the movable frame (120)

In the case of the conventional 3 DOF motion simulator (101) configuredas the above, because there is no DOF to the horizontal direction, thatis, the direction perpendicular to gravity, when creating continuousaccelerating motion or rotating motion as mentioned above, only theforce of gravity is used.

Namely, to create a linear accelerating sensation, the motion simulator(101) drives the plurality of actuators (131′, 132′, 133′) and lifts thefront of the movable frame (120) and thereby allows the passenger (170)to feel a rearward pulling sensation, as depicted in FIG. 5.

In addition, to create rotating movement, the motion simulator (101)drives the plurality of actuators (131′, 132′, 133′) and lifts one sideof the movable frame (120) and thereby allows the passenger (170) tofeel a pushing sensation to the other side, as depicted in FIG. 5.

However, according to the conventional motion simulator (100, 101)configured as the above, both simulators have a structure in which thecenter of gravity of the passenger (170) is above the center of rotationof the movable frame (120).

Due to the above, when representing acceleration from continuous linearacceleration or from centrifugal motion to the side direction, that is,when the movable frame (120) is tilted to utilize gravity, there is theproblem of occurrence of undesired acceleration.

This awkward sensation (that is, force) may be expressed with thefollowing equation

A _(p) =A _(v) +A×R _(pv) +ω×ω×R _(pv)

Wherein, A_(p) is the acceleration vector felt by the passenger of themotion simulator, A_(v)is the acceleration vector of the moving movableframe of the motion simulator, A is rotational acceleration vector ofthe movable frame, R_(pv) is the relative position vector of thepassenger on top of the motion plate, and ω is the rotational velocityvector.

The awkward sensation is sum of the calculation value of the crossproduct of A and R_(pv) vectors, which as A×R_(pv), and the calculationvalue of the cross product of ω, ω, R_(pv) vectors, which is ω×ω×R_(pv).

Namely, n the structure of conventional motion simulators (100, 101),because the center of gravity of the passenger (170) exists verticallyabove the center of rotation of the movable frame (120), when startingto rotate the movable frame to apply an accelerating sensation to thepassenger, the value of the A×R_(pv) vector becomes the oppositedirection of the acceleration intended to be created.

A graph displaying the above is shown in FIG. 7. The dotted line in FIG.7 represents the control reference signals which repeats accelerationand deceleration of 3 m/s², and the solid line represents theac/deceleration sensed by the passenger riding on the motion simulatordriven by inputting the above signals.

In FIG. 7, as shown by the pointed portions bulging out in the oppositedirection of the changes in the reference signals, in contrary to theintended pushing to one side sensation, a sudden attraction to theopposite side is experienced.

As a result of such problems, as shown by the solid line of FIG. 7, amoving sensation in the opposite direction of the moving sensationintended to be created (dotted line of FIG. 7) is applied, andfurthermore, the time taken to track the intended moving sensation isdelayed. This means a decline in actuality experienced by the passenger.

In the case of the 6 DOF motion simulator taken for instance previously,because of the limited range of linear motion, if the movable frame isrotated, a moving sensation opposing the intended moving sensationoccurs as soon as the rotation is initiated.

In the foregoing, the problems of the conventional motion simulator hasbeen described taking the 6 DOF and the 3 DOF motion simulators as twotypes of examples. However, although the extent may vary, the abovementioned problems of conventional motion simulators occur in all motionsimulators having different degrees of freedom that possess functionswhich apply linear accelerating sensations to passengers using rotationand gravitational acceleration, and whose centers of rotation arelocated beneath the passenger.

SUMMARY OF THE INVENTION

Therefore, the technical task that the present invention seeks toachieve, that is, the object of the present invention is to resolve heabove mentioned problems of the conventional motion simulator byproviding a motion simulator that allows moving sensations similar toshe intended sensations and which reduces tracking time, through theelimination of undesired moving sensations when creating movingsensations using gravity.

The above object of this invention is achieved by providing a motionsimulator according to his invention characterized in that it comprisesa stationary frame; a movable frame which is disposed beneath saidstationary frame in the direction of gravity, and which has thepassenger compartment attached on the bottom surface thereof; and adriving device disposed between said stationary frame and said movableframe, which rotationally or linearly moves the movable frame.

According to the motion simulator of this invention, because the movableframe is disposed underneath the stationary frame, the center of gravityof the passenger is lower than the center of rotation of the movableframe.

Namely, because the value of the A×R_(pv) vector is in the samedirection as the acceleration intended to be created even at he point ofrotation commencement, there are advantages in which undesiredaccelerating sensations are not occurred even during accelerationrepresentation using gravity, and the tracking time of the intendedmoving sensation is reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic drawing of the structure of one example of aconventional 6 DOF motion simulator;

FIGS. 2a and 2 b are drawings showing the accelerating sensationcreation procedure of the motion simulator of FIG. 1;

FIGS. 3a and 3 b are drawings showing the rotating sensation creationprocedure of the motion simulator of FIG. 1;

FIG. 4 is a schematic drawing of the structure of one example of aconventional 3 DOF motion simulator;

FIG. 5 is a drawing showing the accelerating sensation creationprocedure of said 3 DOF motion simulator;

FIG. 6 is a drawing showing the rotating sensation creation procedure ofsaid 3 DOF motion simulator;

FIG. 7 is a graph showing a conventional motion simulator being drivenby inputting control reference signals that repeat 3 m/sac/deceleration, and the ac/decelerating sensation sensed by a passengerriding the simulator;

FIG. 8 is a schematic drawing of the structure of the 6 DOF motionsimulator according to one embodiment of this invention;

FIGS. 9a and 9 b are drawings showing the accelerating sensationcreation procedure of the motion simulator according to one embodimentof this invention;

FIGS. 10a and 10 b are drawings showing the rotating sensation creationprocedure of the motion simulator according to one embodiment of thisinvention;

FIG. 11 is a schematic drawing of the structure of the 3 DOF motionsimulator according to another embodiment of this invention;

FIG. 12 is a drawing showing the accelerating sensation creationprocedure of the 3 DOF motion simulator according to another embodimentof this invention;

FIG. 13 is a drawing showing the rotating sensation creation procedureof the 3 DOF motion simulator according to another embodiment of thisinvention; and

FIG. 14 is a graph showing the motion simulator of this invention beingdriven by inputting control reference signals that repeat 3 m/sac/deceleration, and the ac/decelerating sensation sensed by a passengerriding the simulator.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The preferred embodiments of the present invention are described indetail with reference to the annexed drawings.

In FIGS. 8 to 10 b the motion simulator according to one embodiment ofthis invention is depicted. The depicted motion simulator (200) is a 6DOF motion simulator in which the movable frame (220) is driven by sixactuators (231, 232, 233, 234, 235, 236).

According to FIG. 8, the 6 DOF motion simulator (200) as according toone embodiment of this invention includes a stationary frame (210), amovable frame (220), and a plurality of actuators (231, 232, 233, 234,235, 236).

Said stationary frame (210) is installed such that it is fixed relativeto the around (gravity field). Said movable frame (220) is disposedvertically below the stationary frame (210. Underneath said movableframe (220), a passenger compartment (240) is disposed.

Said plurally of actuators (231, 232, 233, 234, 235, 236) are disposedbetween the stationary frame (210) and the movable frame (220) Said eachactuator (231, 232, 233, 234, 235, 236) may be electric, hydraulic, orpneumatic actuators.

Said each actuator (231, 232, 233, 234, 235, 236) is rotatably connectedat both ends thereof by respective pairs of universal joints (231 a and231 b, 232 a and 232 b, 233 a and 233 b, 234 a and 234 b, 235 a and 235b, 236 a and 236 b).

The 6 DOF motion simulator (200) according to one embodiment of thisinvention configured as the above allows the passenger (270) in thepassenger compartment (240) to feel moving sensations similar to thosefelt when actually riding an airplane or automobile by driving theplurality of actuators (231, 232, 233, 234, 235, 236) and thereby movingthe movable frame (220).

For instance, to create a continuous accelerating sensation the motionsimulator (200) drives the plurality of actuators (231, 232, 233, 234,235, 236), as depicted in FIG. 9a, and firstly accelerates the movableframe (220) forward. In the above case, the passenger (270) within thepassenger compartment (240) feels a pulling sensation from the rear dueto the force of inertia, and then when the front of the movable frame(220) is lifted, as depicted in FIG. 9b, the passenger (270) continuesto feel said sensation due to gravity. The rotational movement isstarted while lifting the front of the movable frame (220), however, atthis point the force of inertia a produced from radial acceleration isin the same direction as the force of inertia causing said sensation.Therefore, distinctive from the conventional motion simulator, there isno undesired moving sensation to the opposite direction, and also, inthe present invention, with appropriate adjustment of rotational radialvelocity, the force of inertia may be controlled to the desired amount.

In addition, as another example, to create a rotating sensation fromcentrifugal force, the motion simulator (200) actuates the plurality ofactuators (231, 232, 233, 234, 235, 236), as depicted in FIG. 10a, andfirstly accelerates the movable frame (220) to the side direction.

In the above case, the passenger (270) within the passenger compartment(240) feels a sensation of being pushed in the opposite direction ofsaid movement due to the force of inertia, and then, when he side of themovement direction of the movable frame (220) is lifted, as depicted inFIG. 10b, the passenger compartment (240) continues to feel saidsensation. Also at this point, the rotational movement is started whilethe movement direction side of the movable frame (220) is being lifted,but the force of inertia produced from radial acceleration is in thesame direction as the force of inertia causing said sensation.Therefore, distinctive from the conventional motion simulator, there isno undesired moving sensation to the opposite direction, and also, inthe present invention, with appropriate adjustment of rotational radialvelocity, the force of inertia may be controlled to the desired amount.

On the other hand, in FIGS. 11 to 13, the motion simulator (201)according to another embodiment of this invention is depicted. Thedepicted motion simulator (201) is a 3 DOF motor simulator (201) ofwhich the movable frame (220) is driven by three actuators (231′, 232′,233′).

According to FIGS. 11 to 13, the configuration of the 3 DOF motionsimulator (201) according to another embodiment of this invention isidentical to that of the 6 DOF motion simulator (200) according to theother embodiment of this invention, except that the former has threeactuators (231′, 232′, 233′ and that it is provided with a separatesupport member (250) to limit the occurrence of undesired motion.

Therefore, in describing the configuration of the 3 DOF motion simulator(201) according to another embodiment of this invention, sane referencenumbers are designated for parts identical to those of the 6 DOF motionsimulator (200), and the descriptions thereof are omitted.

As mentioned above, because all motions of the movable frame (220) cannot be restrained with only the actuators (231′, 232′, 233′) in the 3DOF motion simulator (201) according to another embodiment of thisinvention, there is provided a separate support member (250) forlimiting the occurrence of undesired motion to the movable frame (220).

Said support member (250) is composed of a cylinder (251) which is fixedon the stationary frame (210), a piston (252) which moves up and downalong said cylinder, and a universal joint (253) which connects saidpiston and the movable frame (220).

In the case of the 3 DOF motion simulator (201) according to anotherembodiment of this invention configured as the above, because there isno DOF to the horizontal direction, that is, the direction perpendicularto gravity, when creating continuous accelerating motion or rotatingmotion as mentioned above, only the force of gravity is used.

Namely, to create a linear accelerating sensation, the motion simulator(201) drives the plurality of actuators (231′, 232′, 233′) and lifts thefront of the movable frame (220) and thereby allows the passenger (270)to feel a rearward pulling sensation, as depicted in FIG. 12. The forceof inertia produced from radial acceleration at the time of liftingcommencement or the front portion is in the same direction as saidmoving sensation, and when the amount of rotational radial velocity isappropriately adjusted, the desired amount of inertia may be obtainedwithin the control range.

In addition, to create rotating movement, the motion simulator (201)drives the plurality of actuators (231′, 232′, 233′ and lifts one sideof the movable frame (220) and thereby allows the passenger (270) tofeel a pushing sensation to the other side, as depicted in FIG. 13. Theforce of inertia produced from radial acceleration at the time oflifting commencement of the one side is in the same direction as saidmoving sensation, and when the amount of rotational radial velocity isappropriately adjusted, the desired amount of inertia may be obtainedwithin the control range.

According to the above motion simulators (200, 201) according to thisinvention, because both have the movable frame (220) disposed beneaththe stationary frame (210), the center gravity of the passenger (270) isbelow the center of rotation of the movable frame (220).

Namely, because the value of the A×R_(pv), vector is in the samedirection as the acceleration intended to be created, even duringrepresentation of accelerating sensations using gravity, undesiredaccelerating sensations to the opposite direction are not produced, andthe tracking time of the desired moving sensation may be reduced.

A graph displaying the above is shown in FIG. 14. The dotted line inFIG. 14 represents the control reference signals which repeatsacceleration and deceleration of 3 m/s , the imaginary line representsthe ac/deceleration sensed by the passenger riding on the conventionalmotion simulator driven by inputting the above signals, and the solidline represents the ac/deceleration sensed by the passenger riding onthe motion simulator of the present invention driven by inputting saidsignals.

According to the graph, in the case of he motion simulator of thisinvention, there are no portions sharply bulging out in the oppositedirection of the change in the reference signals as in the case of theconventional simulator. This means that undesired moving sensations arenot sensed, and as a result, means reduction of tracking time for themoving sensation (dotted line of FIG. 14) intended to be created, asshown by the solid line in FIG. 14. In addition, in case of riding anactual motion simulator, the two types of sensations show a largedifference in the aspect of motion reality. That is, a great differencein the performance of the motion simulator is displayed.

It is to be understood, however, that even though the present inventionhas been described with reference to the annexed drawings which depictthe preferred embodiments thereof, the present invention is not limitedto the said embodiments, and may apparently be modified in many ways bythose ordinarily skilled in the art without departing from the generalprinciple and scope of the invention expressed in the appended claims.

What is claimed is:
 1. A motion simulator comprising: a stationaryframe; a movable frame which is disposed beneath said stationary framein the direction of gravity, and which has a passenger compartmentattached on the bottom surface thereof; and a driving device disposedbetween said stationary frame and said movable frame, which rotationallyor linearly moves the movable frame.
 2. The motion simulator of claim 1,wherein said passenger compartment is disposed beneath said movableframe in the direction of gravity, and thereby the center of gravity ofthe passenger in said passenger compartment is lower than the center ofrotation of said movable frame in the direction of gravity.